Abstract: The application of immune-based therapies to augment the anti-tumor immune response following autologous and allogeneic blood or marrow transplantation (BMT) has dramatically increased over the past several years. Reconstitution of the immune system following BMT, graft-versus-host disease (GVHD), and post-grafting immunosuppression may modify any immunotherapeutic approach. The need to carefully evaluate, and monitor the immune response in this setting has become Increasingly apparent In addition, recent studies indicate that the in vivo transfer of immune reactive cells expanded ex vivo can augment the anti-tumor effect of BMT. The principal objectives of the Immunologic Monitoring and C ell Processing Core are to provide state-of-the-art immunologic techniques to characterize and quantify human immune responses in support of the research projects of this program project grant and to provide the cell processing expertise to support the clinical laboratory requirements of this program project grant. While there is great diversity in the therapeutic modalities being evaluated, most areas strongly overlap with regard to analysis and characterization of the immune response. A wide-variety of techniques that enumerate and characterize antigen-specific T cells, assess their functional behavior ex vivo, evaluate the diversity of the T cell response as well as expand T cell populations ex vivo are currently available to the research projects within this Program Project. Therefore, the specific aims of this Core are to: 1. Provide technical expertise and conduct assays to monitor and characterize the immune response. 2. Establish standard operating procedures and quality control for all immunological assays. 3. Provide technical support to identify and develop assays specific for all projects. 4. Serve as a repository for donor and patient peripheral blood lymphocytes. 5. Immunologically activate and expand ex vivo patient-derived marrow infiltrating lymphocytes (aMILs). 6. Serve as the quality and regulatory support for the clinical laboratory component of the aMILs trials.